40 subjects aged 17-24 years who were diagnosed in our clinic ten years previously as having chronic sustained hyperactivity, will be re- evaluated on a number of different measures. These will include a careful history (as to marital status, work and school record, antisocial behaviour and psychiatric illness or hospitalisations), a psychiatric evaluation, a test of personality, two tests of cognitive style and an electroencephalogram. Control subjects, matched with the experimental subjects, will be re-evaluated on the same measures. The aim of the project is to determine the prognosis of hyperactivity in childhood with respect to adult life.